Tail skid



July 1 1924. 1,501,601

E. H. HERBIG TAIL SKID Filed June 9, 1922 2 Shunt-Shoot l smummmunnumum- ITLVBIflIE-II'.

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W M z 'f July 15 1924. 1,501,601

E. H. HERBIG TAIL SKID Filed June 9, 1922 2 Shoots-Shoat 2 /0 2': arm(1:; as

Wan-3S3 Invlarflar and Patented July 15, 1924.

UNITED STATES PATENT OFFICE.

ELWO'OD H. HEBIBIG, OF DAYTON, OHIO, ASSIGNOR TO DAYTON-WRIGHT COMPANY,OF DAYTON, OHIO, A CORPORATION OF DELAWARE.

TAIL SKID.

Application filed June 9, 1922. Serial No. 567,035.

To all whom it may concern:

Be it known that I, Enwoon H. HERBIG, a citizen of the United States ofAmerica, residin at Dayton, county of Montgomery,

tate of Ohio, have invented certain new and useful Improvements in TailSkids, of which the following is a full, clear, and exact description.

This invention relates to tail skids for airplanes or to any ground skidattached to a vehicle for a purpose similar to that of the airplane tailskid.

This invention is characterized especially by compactness, greatstrength, light weight, and simplicity of construction, the number ofparts being reduced to a minimum, and the forces bemg carried to thesupporting body or fuselage directly in all cases.

An especial object of this invention is to provide a simple stop meansfor preventing a dangerous de ection of the skid under excessive load orin case of a failure of the yield able restraining means, and also therestraining means may be put under an initial load and thus hold theskid firmly in its normal .position when not under load.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein preferred forms of embodiments of the presentinvention are clearly shown.

In the drawings:

Fig. 1 is a plan view of an airplane tail skid and associated parts of aWelded tube fuselage.

Fig. 2 is a side elevation thereof, and shows in dotted lines theposition of the upper end of he skid at extreme deflection.

Fig. 3 is a rear elevation of the tail skid parts taken on line 33 ofFig.2

In the drawings, like characters of reference designate like orcorresponding parts. Numeral 1O designates the two upper longrons and 11the two lower longrons, 12 an upper horizontal strut, 13 a lowerhorizontal strut, and 14 side struts of a bulk head designated in itsentirety by numeral 15, of the welded tube fuselage in connection withwhich my invention has been shown. The upper horizontal strut 12 of thebulk head 15 is further braced by the strut 16 which extends from thecenter of strut 12 to the rear tip of the fuselage where the longrons 10are secured to the tail post 18, and the lower horizontalstrut 13 issimilarly braced by the strut 17.

The bulk head 15 is provided with an upper bearing 20 at the point ofintersection of struts 12 and 16 and a lower bearing 21 at theintersection of struts 13 and 17 for rotatably mounting the verticaltube 25 therein. The skid 26 is pivoted on a horizontal pivot pin 27tothe lower projecting end of tube 25. The fitting 28 for the pin 27 ispreferably fastened to, the tube 25 by being provided with a shank whichextends a suitable distance within tube 25 and is held therein by anysuitable means, as by brazing. The fitting 30 is secured to the skid 26in any suitable manner as by means of bolts, screws, or pins, and ismade strong enou h to take the entire upward load on the sk1d shoe 31when the skid contacts with the ground in landing. This upward load. istransmitted through the vertical tube 25 to the thrust bearing 20, thethrust being delivered by the bronze collar 32, which is secured to thetube 25 preferably by means of pins 33. The horizontal strut 12 isbraced-to withstand this upward thrust by the tie rods or wires 35 whichrun diagonally downward to the lower longrons 11. (See Fig. 3.) Anadvantage is obtained by this arrangement of carrying the thrust firstto thetop part of the fuselage frame and then transmitting it down tothe lower longrons by tie braces, since these tie braces are in tensioninstead of compression, as would be the case if braces were used tocarry the thrust from the lower part of the frame to the top longrons.

The bulk head 15 is preferably further braced along the sides and topand bottom of the fuselage by the usual diagonal 'brace wires 36 and 37,as illustrated in the drawings.

The upper end of skid 26 is guided by aguide rod 40 when the skid pivotsupon the pin 27. This rod 40 is pivoted at 41 upon the collar 32 andpasses through a slot 43 in the upper end '.of skid 26, this slot 43being of somewhat greater depth than the diameter of the rod 40 topermit an angular movement of the rod therein, as shown in dotted linesin Fig. 2. Rigidly secured upon rod 40 are the two stops 44 and 45 whichdetermines the limiting positions of skid 26 when under no load and whenat maximum deflection respectively. The upper end of skid 26 is heldyieldably against stop 44 by the shock absorber cord 50 WhlOl'i' isattached to the collar 32 by means of the shackle. 46 pivoted to thecollar by pin 47. Preferably the shock absorber cord 50 is attached tothe shackle 46 and to the skid 26 by being looped over small sheaves 48which are rotatably mounted in shackle 46 and in a fitting 49 attachedto the upper end of skid 26. Now it is clear that when skid 26 contactswith the ground in landing, theshock absorber cord 50 is stretched toallow the skid to pivot on pin 27 and the upper end of the skid willmove downwardly toward the dotted position shown in Fig. 2, the rod 40and the shackle 46 pivoting on pins 41 and 47 respectively to causethese parts to be in direct tension at all times. if the force on theskid shoe 31 is excessive or if the cord 50 or its connections shouldbreak, the stop 45 on rod 40 will limit the movement of the skid andprevent either end of the skid from doing damage to the fuselagestructure, and will also prevent the tail of the fuselage from droppingdown in dangerous proximity to the ground. In other words, stop 45 willso act as to render, an emergency skid, which is sometimes employed,unnecessary.

In case of a side motion of the tail in landing or taxiing, the entirestructure of skid 26, tube 25, collar 32, rod 40 and cord 50 may rotatewithin the vertical. bearings 20 and 21., and. this rotation may occurentirely independently of the pivoting of skid 26 on pin 27. Thus theuniversal mounting of the skid will automatically accommodate any motionto which the skid will be subjected.

As an aid in guiding the plane when running over the ground means areprovided for interconnecting the vertical rudder with the tail skid 26so that they both cooperate to cause the plane to turn in the desireddirection. The rocker arms 60 are rigidly se-- cured to the verticaltube 25, preferably by means of being welded to a collar 61 which inturn is pinned to tube 25 by means of pins 29 as shown. This collar 61also acts to prevent tube 25 from dropping down through bearing 21 dueto the weight of the skid 26 and its associated parts during flight. Thecables 65 are attached to the ends of arms 60 by suitable means and areinterconnected with the corresponding cables (not shown) which operatethe vertical. tail rudd. This interconnection may be made either byrunning cables 65 all the way to mentor the foot rudder bar commonlyused to op erate the rudder or by connecting cables 65 to the cables(not shown) leading from the rudder operatlng means back to the ruddermasts. The tension springs 66 are preferably inserted in cables 65 inorder to relieve the operator of violent jerks and vibrations whichwould be transmitted to the operatin means when the tail skid 26 runsover roug ground.

While the forms of mechanisms herein shown and described, constitutepreferred forms of embodiments of the present invention, it is to beunderstood that other forms might be adopted, all coming within the S00e of the claims which follow.

l hat I claim is as follows:

1. A tail skid for airplanes including a skid bar having universal pivotconnection to the body of the airplane to permit the skid to swing inany direction, and a single stop means engaging the skid above its pivotto limit both the up and down movement of the skid.

2. A tail skid for airplanes including a skid bar having universal pivotconnection to the body of the airplane to permit the skid to swing inany direction, and stop means engaging the skid above its pivot to limitboth the up and down movement of the skid, said stop means beinsupported from the airplane body at a point substantially vertical abovethe skid bar pivot.

3. A. tail skid for airplanes including a skid bar mounted upon itssupport so that it will pivot about both a vertical and hori-- zontalaxis, and stop means engaging the upper part of the skid for limitingthe upward movement of the skid about the horizontal axis at all times,said stop means being mounted upon the airplane to swing with the skidbar whenever said bar pivots on its vertical axis.

4. In combination with an airplane, a. ground skid having universalmounting upon said airplane, and a stop means for said skid havinguniversal mounting attachment to said airplane.

5. In combination. with an. airplane, a. ground skid having universalmounting upon said airplane, and a stop means for said skid havinguniversal mounting attachment to said airplane, said stop means engagingthe upper part of said skid.

6. In combination, a rigid body, a ground skid having universal mountingupon said body, said skid being yieldably held in normal position whennot under load, and I. single stop means engaging said skid to preventexcessive deflection. thereof in two directions.

7. In combination, a rigid body, a. ground skid having universalmounting u on said body, said. skid being yieldably hel in normalposition when not under load, and stop means engaging said skid toprevent exces In testimonywhereof I hereto aflix my sive deflectionthereof in two directions, said signature.

stop means including a rigid member pivotally mounted upon said body andguided by ELWOOD HERBIG' 5 the upper portion of said skid, and stopWitnesses:

means on said member for engaging said Gno. E. PASOO,

skid. Wu. P. P4500.

